setprecision() in C++

Description:

It is used to set the decimal precision to be used to format floating-point values on output operations.

#include<iomanip> is required to use setprecision.

Declaration: 

setprecision(n);

Example:

Let's understand setprecision with a couple of examples.

#include<iostream>

#include<iomanip>

using namespace std;

int main(){

double n = 3.141516;

cout<<setprecision(5)<<n<<"\n";

cout<<setprecision(4)<<n<<"\n";

cout<<setprecision(3)<<n<<"\n";

cout<<setprecision(2)<<n<<"\n";

}

Output:

3.1415

3.142

3.14

3.1

----------------------

setprecision with fixed:

setprecision coupled with fixed will allow you to manipulate only the part after decimal point.

Example:

Let's understand setprecision with a couple of examples.

#include<iostream>

#include<iomanip>

using namespace std;

int main(){

double n = 3.141516;

cout<<fixed<<setprecision(5)<<n<<"\n";

cout<<fixed<<setprecision(4)<<n<<"\n";

cout<<fixed<<setprecision(3)<<n<<"\n";

cout<<fixed<<setprecision(2)<<n<<"\n";

}

Output:

3.14152

3.1415

3.142

3.14

As you can see the part after decimal point is manipulated.